Abstract

NASA has its sights set on exploring Mars, and one of the major keys to success will be Liquid Oxygen-Liquid Methane (LO2/CH4) Propulsion Technology, an area of research for UTEP’s NASA-funded Center for Space Exploration Technology Research (cSETR), led by Dr. Ahsan Choudhuri. With the help of a grant from NASA, the cSETR at the University of Texas at El Paso is working on a number of projects related to LO2/CH 4. The project that will be discussed in detail here is the Daedalus project, a sub-orbital space vehicle launched by a sounding rocket that will test the feasibility of LO2/CH4 as the propellant source for both its main engine and reaction control engines in vacuum and low gravity conditions. This thesis details the selection of the launch vehicle, and the process of establishing the Daedalus structural design based on the launch vehicle’s payload envelope requirements. After narrowing the launch vehicle down to two options offered by the NASA Sounding Rocket Program (NSRP), the Black Brant IX launch vehicle was selected based on the conclusion that its capacity for propellant storage allows 77 seconds of total main engine run time at full thrust, superior to the 35 second run time capability calculated for the smaller Terrier-Improved Orion launch vehicle. This selection was followed up by the development of the Daedalus payload structure, and FEA simulations were conducted on the model to specifically simulate the acceptance tests required for all new payloads prior to launch approval. The design was largely successful, except for stresses exceeding the failure criteria at the interface of the main engine and the payload structure, as a result of a 30-g acceleration in the axial thrust direction, as well as vibrational loads at a frequency of 42 Hz, the model’s second natural frequency. After addressing model’s shortcomings in this area, the Daedalus payload design presented in this thesis should be a guideline moving forward with design of Daedalus’ first prototype.